A new ancient killer fish fossil found in Canada has been described for the first time. The extinct species of ‘rebel coelacanths’ is thought to have been a quick-swimming predator with a forked tail like that of a tuna. Coelacanths were dubbed ‘living fossils’ after they were thought to be extinct, but one was discovered in 1938 in South Africa.

The living coelacanths are slow swimmers with strange triple-lobed broad tails, unlike the shark-like three-foot fish, which lived around 240 million years ago.

Dr John Long, from the Natural History Museum of LA County, Los Angeles, who is a fish fossil expert, but did not contribute to the study, says, “This…